SCS Coverage Raising Location Challenges for Pinpointing Emergency Calls

Emergency calls made over terrestrial networks are routed to the proper public safety answering point (PSAP) based on fairly precise location data about the caller that comes from the cellsite location or network-based location, said Intrado Vice President-Technology John Snapp. Satellite coverage is in the form of one large beam that’s a lot larger than the range of an individual cellsite, he said. GPS or Wi-Fi location data might be gleaned from the handset, but it could take many seconds to obtain, he said. Snapp said it would likely make sense not to wait but to route calls immediately to a national or default call center that can obtain information about the call's nature and relay that to the appropriate PSAP agency. Several national 911 centers now serve as default backup for needs such as VoIP calls and would likely play that default role for SCS calls, he said.

Even the largest cellsites have coverage areas much smaller than satellite beam coverage, said Mike Hooker, T-Mobile senior MTS systems architecture director.

There also could be challenges in tackling emergency calls originating in areas outside the coverage of traditional PSAPs, such as offshore, Snapp said. Incorporating the Coast Guard into 911 networks might be necessary, he added.

Emergency responsiveness is a core market for direct-to-device (D2D) services including SCS, especially in areas without a good terrestrial network, said Kara Leibin Azocar, Iridium vice president-regulatory. She said use of a default or national emergency call center is critical to connectivity.

Lynk Global has five commercially licensed satellites in orbit and is offering SCS service -- using terrestrial mobile network operator (MNO) spectrum -- in seven countries. As such, providing emergency services access “is not theoretical for us,” said Margo Deckard, Lynk Global chief operating officer. SCS services will potentially extend the geography from which PSAPs receive calls, making it incumbent on providers to ensure callers' locations are available, she said.

SpaceX aims to activate its D2D service this fall, said David Goldman, SpaceX vice president-satellite policy. He said SpaceX is launching its D2D satellites in earnest, including 13 on Tuesday. With testing of its D2D satellites showing them exceeding expectations, SpaceX will ramp up its launch activity over the summer, he said. While its D2D partnership with T-Mobile will support texting and limited data services at first, SpaceX will make its service more robust over time as it adds satellites, he said.

The FCC's March SCS framework order (see 2403140050) allows routing of 911 calls using either location-based routing or sending them to a default emergency call center, said Renee Roland, FCC Public Safety and Homeland Security Bureau lawyer. She said the agency thought such flexibility was warranted given SCS' nascent nature.

For regulatory approval, terrestrial providers must file a lease arrangement with the FCC that covers an entire geographically independent area, including the continental U.S., said Stephanie Neville, FCC Space Bureau lawyer. If a wireless provider lacks enough spectrum, it can create a consortium with other wireless providers that collectively strike an agreement with a satellite operator, she said.

Asked what role the FCC might have in helping consumers understand the differences between SCS service using terrestrial spectrum or a D2D service that employs mobile satellite spectrum, agency staffers lacked answers. Azocar said such education might be unnecessary because consumers likely wouldn’t see a difference in coverage via either MSS or SCS delivery.

MNOs have different approaches about what customers see, Deckard said. She said some want subscribers to know when they are on a degraded service, so it’s evident on the handset that they are on Lynk service. Other MNOs “want to take ownership” of the coverage, especially when it's in areas they have never reached before, so their subscribers never know they’re off the MNO’s terrestrial network, she said.